As expected, a lower back problem has ruled Mark Cueto out of England's World Cup opener against Argentina on Saturday, resulting in a start on the left wing for Delon Armitage.

Cueto suffered the injury in his country's final warm-up clash, against Ireland in Dublin last month, but it was initially thought that he would be fit to face the Pumas. However, it emerged on Wednesday that Cueto was still in real discomfort and that the decision had already been taken to replace the Sale Sharks ace with London Irish fullback Delon Armitage, who scored a try after coming on as a replacement against the Irish.

It was reported that Cueto's back complaint is likely to rule him out action for at least two weeks, thus putting his hopes of playing any part in the pool stages in real jeopardy. However, England team manager Martin Johnson insists that the problem is not that serious.

"Mark's had a little bit (of back trouble) before but he could have played (against Argentina)," the World Cup winner said. "There's a grey area between fit and injured in where most players sit all of the time. He trained fully all week but he's not quite where he needs to be - but the good things for us is Delon is playing very well.

"It's quite a simple decision. Delon been around for a few years now, we know when he is in form he is a Test match player. We've no qualms about picking him in any of the back three positions."

Armitage's promotion to the starting line-up is one of two changes in personnel to the side which defeated Ireland, with Nick Easter, who was forced to withdraw from the game because of a calf strain, returning to the back-row in place of Hendre Fourie. Easter's inclusion sees James Haskell switch to openside flanker in the continued absence of captain Lewis Moody, who is still struggling with a nagging knee injury.

There are also two changes amongst the replacements. The fit-again Ben Youngs, who missed all of England's warm-up games after being forced to undergo knee surgery, preferred to Joe Simpson as cover for scrum-half Richard Wigglesworth, while Tom Wood gets the nod ahead of Simon Shaw.

The absence of Moody means that Mike Tindall will serve as skipper in what will be his 73rd appearance in Test rugby, which is a record for an England centre. Tindall had shared the record with former England captain Will Carling.